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s <br />`fI <br /> c <br /> APPENDIX A <br /> INVESTIGATIVE PROCEDURES <br /> Exploratory Soil Boring and Monitoring Well Installation <br /> the soil borings were drilled using hollow-stem auger drilling equipment. The borings <br /> were logged by a PACIFIC geologist using the Unified 'Soil Classification System and <br /> standard geologic techniques. Soil samples for "Logging and chemical analysis were <br /> collected at depth intervals of 5 feet by advancing a California modified split-spoon <br /> sampler with brass sample liners into undisturbed sail beyond the tip of the auger. The <br /> sampler was dr_ven a maxinawn of 1$inches using a 40-pound hammer with a 30-inch <br /> drop. Soil samples for chemical analysis were retauied in the brass liners and capped <br /> with aluminum.foil and plastic end caps, a*d se2lea in clean glass jars. The samples <br /> were plac,s,d on ice and transported to the labora-wry accompanied by the a)propriate P; <br /> chain-of-custody documentation. The drilling equipment was steam-cleaned between <br /> each boring. <br /> The borings were converted to groundwater monitoring wells with the installation of <br /> 3-inch diameter flush-threaded Schedule 40 PVC casing and 0.020-inch factory-slotted <br /> screen. drade.d sand pack was placed ra the artriular space across the screened interval <br /> and eictends.,;approllately' 1>root. above the screened sentions: A bentonite and <br /> concrete seal was placed from t op of the sand pack to the ground surface. A locking <br /> cap and protective vault box were installed on the top of each well. Following well <br /> completion,well elevations were surveyed to the nearest 0.01 foot relative to mean sea <br /> level datum by a licensed surveyor. <br /> Organic Vapor Analysis <br /> Soil samples c,liected during drilling were analyzed in the field for ionizable organic <br /> compounds using the HNU Model.,P.140I"p oto-ionization detector with a 10.2 eV <br /> :amp. The test procedure involves measuring approximately 30 grams from an undis- <br /> turbed soil sample, placing this sub-sample in a clean glass jar, and sealing the jar with <br /> aluminum foil Fecured under a ring-type.threaded lid. The jar is warmed fo,approxi. <br /> mately 20 minutes,i:ien the foil is pierced an,d the head-space within the jar is tested for <br /> 311,010 REPORT c <br /> i A- 1 February 13,1)91 <br />